Russia has bombed ISIS in the heaviest strikes in eastern Syria since the war began, as its military maneuvers in the Mediterranean forced Lebanon to reroute flights, AFP reports.

The United Nations, meanwhile, passed a motion calling for action against ISIS, a week after a series of shootings and bombings in Paris left 130 people dead, sparking international condemnation and fears of similar attacks elsewhere in Europe.

Russian and Syrian warplanes carried out more than 70 strikes in eastern Deir Ezzor province Friday, killing at least 36 people including 10 children, the Syrian Observatory for Human Rights said.

The Britain-based group said the raids hit several cities and towns as well as three oilfields, in the heaviest bombardment there since the conflict began in March 2011.

Most of the province, including large parts of its capital, is held by ISIS.

The regime still controls the military airport and several smaller areas.

Fighting raged Saturday between IS and regime forces around the airport, a day after clashes killed 30 people, 22 of them ISIS terrorists, according to the Observatory.

Russia began its bombing campaign in support of President Bashar al-Assad on September 30, and pledged to step up the strikes after IS claimed that a bomb downed a Russian passenger jet over Egypt last month, killing all 224 people on board.